The present invention relates generally to a hunting arrow or bolt and, more particularly, to a chemical indicator signifying whether a game animal was shot by the arrow or bolt.
In archery hunting, shot placement is very critical to ensuring a quick and humane kill. Archers practice for hours to make sure they make ethical shots when hunting. The most desired shot by an archery hunter is referred to as a “double lung” shot where the arrow or bolt passes through both lungs of an animal standing broadside to the hunter. With today's compound bow and crossbow technology, it is very difficult to determine where the arrow or bolt has gone once it leaves the bow or crossbow due to the speed that the projectile is traveling. Many crossbow bolts are traveling at velocities approaching 400 feet per second. The projectile velocity also means that the arrow or bolt frequently passes completely though the animal.
Archery hunters are generally physically close to their prey when taking a shot, generally forty yards or less. Deer may often sense a hunter's presence and be additionally alert. Deer often hear the release of the arrow from the bow before the arrow reaches them which allows them to initiate movement. This movement can affect the impact point of the arrow or bolt. A broadside shot when aimed can quickly become a quartering shot in which the arrow impacts the animal at an angle, either from the rear to the front or from the front to the rear, which may not be as lethal as the desired transverse double lung shot. Such quartering shots are more likely to result in an arrow passing at least partially through the animal's digestive tract.
Given the difficulty of observing the arrow during its flight to the target, hunters usually seek the arrow afterward in order to examine it for indications of the shot. An arrow having hit its target will be covered in blood and other fluids from having passed through the target animal.
U.S. Pat. No. 9,121,678 to Kendall discloses the use of a “blood ring” on an arrow which is a region that allows absorption of fluids as an arrow or bolt passes through an animal. This region may be provided with a textured surface for collecting blood that is then visually inspected by the hunter. A simple observation of the presence of blood does not provide any indication of whether the shot is a humane shot (e.g., double lung) or a gut shot in which the arrow or bolt passes through other portions of the animal.
Animal blood is generally neutral, having a pH in the range of 7.35 to 7.45. Shots passing through the animal's lungs would be exposed to primarily to blood. Digestive fluids in the animal's gut are highly acidic, generally having a pH ranging from 1 to 4.5. A shot passing thorough the animal's gut is likely to be exposed to digestive fluids in addition to blood. A variety of chemical compounds are known to exhibit color changes upon contact with fluids of various pH, specifically including color changes when contacting acidic fluids.
It would be advantageous to provide an indicator capable of detecting and indicating pH by a visible change in color that would provide an immediate indication of a gut shot that would permit the hunter to determine how the animal should be tracked. If an indicator shows that the animal has been hit in the stomach region (a gut shot), it is best for the hunter to back away and allow the animal to lay down and die rather than to pursue it immediately. When hunting deer, an animal that has been gut shot is often left to lay overnight if weather conditions allow so as not to jump it from its bedded location which can easily cause the wounded animal to travel as much as a mile before bedding down again. Conversely, if the indicator shows a clean, non-gut shot, has occurred, the hunter can begin tracking the animal in a normal practice of waiting a short time (one-half hour).